Traveling wave tube



Jan. 12, 1960 KLElN ETAL 2,921,225

TRAVELING WAVE TUBE Filed Sept. 2, 1955 IN VEN TORS. WERNER KL 'lN WALTEE Ffl/Z A 7' TGRNE Y United titates Patent TRAVELING WAVE TUBE WernerKlein, Korntal, Wnrttemberg, and Walter Friz, Stuttgart, Germany,assignors to C. Lorenz Alrtienge sellschatt, Stuttgart-Zulienhausen,Germany, a torperation of Germany Application September 2, 1955, erialNo. 532,322

Claims priority, application Germany September 3, 1954 5 Claims. (Cl.3153.6)

In our copending application Serial No. 499,163 filed April 4, 1955, nowPatent No. 2,857,547 issued Oct. 21,

1958, a tube structure is shown wherein a connecting pipe between pairsof cylinders at the input and the output ends of the tube servesmechanical as well as highfrequency purposes, particularly thesuppression of unwanted high-frequency feedback. The exclusion offeedback paths is achieved by suitably dimensioning the pipe, as statedin the main patent, and by attaching a damping layer to the dielectricpipe. When such a tube is provided with a plurality of galvanicallyseparated helices then a corresponding number of lead-in conductors willbecome necessary for the individual helices. In most of such cases, andin order to obtain a suitable structural shape of the tube, theselead-in conductors will be led through the wall of the vacuum containerof an existing socket. These metallic lead-in conductors would thenproceed along the helices and would inherently act as a feedbackcircuit.

In accordance with the invention it is therefore suggested to employ thedamping layer or coating of the dielectric pipe as the helix connectingline for the added helix. It is also possible, by longitudinallydividing the damping layer into galvanically separated paths, to connecta plurality of helices or cavities lying along the length of thishelical arrangement or to connect conductive layers attached to theinsulating body surrounding the electron beam for the purpose ofavoiding any charging phenomenae, or to connect a modulating cylinder,with a terminal of the socket connections. Since the charging rate ofthe helices or of the other mentioned electrodes respectively, is smallin any case, the somewhat increased lead-in resistance of the dampinglayer will not be detrimental. Accordingly, the special lead-inconductors with their unwanted feedback effects, will also be done awaywith.

The invention will now be particularly described with reference to anexemplified embodiment.

The accompanying drawing shows the helix zone of a traveling wave tubeemploying e.g. two separated helices 1 and 2. These helices are held inposition by the ceramic bars 3. Helix 1 is in metallic connection withthe pair of cylinders 4, 5 and helix 2 with the pair of cylinders 6, 7by means of the antennas 8 and 9 respectively. The ceramic bars 3 arereceived and supported by apertures provided in the bottoms of thecylinders 4 and 7. The dielectric pipe 10, that is provided with ICC adamping layer 11, forms the mechanically rigid connection between thetwo pairs of cylinders 4, 5 and 6, '7. The damping layer 11 also extendsover the mechanical joint between pipe 10 and cylinder 6, but isseparated from the cylinder 5 by a ring-shaped uncoated portion of thepipe. The helix 2 is connected via the antenna 9, the cylinder 6, theflange ring 12, th damping layer 11, the clip 17, and the connectingwire 15 which is led through the little insulating tube 14 arranged inthe profiled component 13. The helix 1 is connected to the connectingline 16 by the antenna 8 via the cylinder 5, the profiled component 13and the cylinder 4.

Of course, a damping layer applied to the inside of the dielectric pipemay take over the function of further connecting lines.

What is claimed is:

1. A traveling wave tube comprising two coaxial successive helical delaylines insulated from one another, a tube of dielectric materialsupported in coaxial spaced relation with said helices and extendingtherealong substantially to the opposite ends thereof, a socket terminalat one end of said tube having a plurality of terminal pins, aconductive attenuating coating on the dielectric tube insulated from thehelix at the socket end of said tube and conductively connected to theother helix, said coating being in the form of galvanically separatedtracks, whereby several independent terminal connections may be made, aconnection from one of said terminal pins to the helix near said socketend, and a conductive connection from another terminal pin to saidconductive coating, whereby independent operating voltages may beapplied to said helices.

2. A traveling wave tube as claimed in claim 1, characterized in thatone said track of the damping layer serves as the connecting line for amodulating electrode.

3. A traveling wave tube as claimed in claim 1, characterized in thatwith traveling wave tubes employing n helices at least nl tracks of thedamping layer serve as connecting lines for n1 helices.

4. A traveling wave tube as claimed in claim 1, characterized in that atleast one track of the damping layer serves as the connecting line for acavity arranged in the course of the helix arrangement.

5. A traveling wave tube as claimed in claim 1, characterized in that atleast one track serves as connecting line to an arrangement serving toavoid any charging phenomena.

References Cited in the file of this patent UNITED STATES PATENTS2,487,332 Hagen Nov. 8, 1949 2,585,582 Pierce Feb. 12, 1952 2,602,148Pierce July 1, 1952 2,660,689 Touraton et a1. Nov. 24, 1953 2,766,398Orthuber Oct. 9, 1956 2,806,177 Haeff Sept. 10, 1957 2,806,974 HaeflSept. 17, 1957 2,841,739 Pierce July 1, 1958 FOREIGN PATENTS 668,725Great Britain Mar. 19, 1952

